RU2765381C1 - Method for processing raw materials containing keratin into an easily digestible protein concentrate: feed additive - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to agriculture. A method for processing raw materials containing keratin into an easily digestible protein concentrate, a feed additive, is characterized by the fact that the raw materials containing keratin are roughly crushed, as which bird feather and down, wool and bristles are used, to a particle size of no more than 5 mm, then it is finely ground to a particle size of no more than 0.2 mm, the grinding is homogenized by stirring and heating in the temperature range from 30 to 60°C with the addition of water, the heated mass is fermented with an enzyme containing keratin-splitting proteases, the fermented mass is separated into liquid and solid fractions, the solid insoluble precipitate is repeatedly subjected in the specified cycle to fine grinding, homogenization, fermentation and separation until its complete fermentation.

EFFECT: invention makes it possible to increase the processing time of keratin-containing raw materials, obtain a rich complex of amino acids in the resulting protein product and ensure its digestibility at a level of at least 85% with environmental cleanliness and low energy costs.

1 cl, 2 dwg, 1 ex

Description

The invention relates to a technology for obtaining a protein product from feather-down and other keratin-containing raw materials (KSS).

The inventive method can be used at livestock enterprises to obtain an important feed additive for animal husbandry - an easily digestible amino acid complex. It is known that keratins are distinguished by a high mass percentage and a balance of essential amino acids for various farm animals, which is similar in relation to meat. However, keratins cannot be digested by animals due to their insolubility in water and gastric juice, which necessitates the use of methods for their processing prior to direct consumption.

From the prior art there are various methods for the processing of KSS, for example, feathers and fluff of birds, horns, hooves, as well as skin and wool of agricultural animals unsuitable for dressing, based on existing types of hydrolysis: chemical, hydrothermal and enzymatic, (see, for example, Antipova L .V., Shamkhanov C.Yu. Bioconversion of feather keratin under the action of various enzyme preparations // Izvestiya VUZov, Food Technology, No. 2-3, 2004, pp. 33-35).

A known method of processing KSS for animal feed using chemical hydrolysis, see patent SU 459209 A1, publ. 02/05/1975, in which the raw material is boiled in water, dried and ground into flour, then treated with an alkali solution in two stages, without heating at a temperature of 15-25 ° C for 1-5 days and heated to a temperature of 90-95 ° C within 6-10 hours, and the resulting mass is neutralized with acid. The disadvantages of the known method are its limited use only for the processing of horns and hooves, a long processing time, and the use of hazardous alkali and acid in the processing.

Another version of the chemical hydrolysis of keratin at a temperature of 133 to 152°C is used in a method for obtaining protein hydrolysates of complete amino acid composition from keratin and other protein raw materials, see patent SU 294828 A2, publ. 02/04/1971. The proposed method uses commercial hydrochloric acid (on average 0.5 kg per 1 kg of the output product), which makes processing dangerous and unecological. Another disadvantage is the relatively long duration of the hydrolysis process from 6 to 10 hours without taking into account the time for the preparation of raw materials.

A method for processing KSS using hydrothermal hydrolysis, see patent SU 1757580 A1, publ. 08/30/1992, eliminates the use of hazardous substances and ensures rapid processing of raw materials using water-heat treatment at 120-140 ° C for 20-40 minutes, followed by extrusion at a mass fraction of moisture in the mixture of 15-19%, a pressure of 4-5 MPa within 15-30 s. However, the end product is characterized by a relatively low digestibility (digestion) from 67.3% to 76.1%) in the above application examples.

In a more modern method of processing feather-down KSS using hydrothermal hydrolysis, see patent RU 2683560 C1, publ. 03/28/2019, moisture is initially removed from the input raw material by squeezing by passing it through twin screws, then the squeezed raw material with a moisture percentage of not more than 45% is pressed under a pressure of 1 to 20 MPa by scrolling between the twin screws with the raw material fed to the sealing cones, compacted the raw material is then loosened with augers and heated to a temperature of 180 to 260°C, subjected to hydrolysis, the resulting mass is cooled by unloading into a receiving ventilated chamber, then dried to reach 8-12% humidity. The resulting protein product has a good percentage of digestibility - not less than 85%), which meets modern requirements for feed additives. The disadvantage of this method is the high energy costs for the processing of raw materials, which follows from the need to expose it to high temperatures from 180 to 260°C and pressures from 1 to 20 MPa. Another disadvantage is hard high-temperature hydrolysis, which leads to the destruction of some useful amino acids (see, for example, Korochanskaya S.P., Storozhuk P.G., Bykov I.M. Educational and methodological manual on biological chemistry. - Krasnodar: 2015, p. 12), which negatively affects the quality of the protein product.

The closest analogue to the claimed method is a method for processing KSS, see patent SU 1397018 A1, publ. 05/23/1988, using enzymatic (soft) hydrolysis at temperatures from 37 to 45°C. In this method, the raw material is loaded into a digester, poured with water in a ratio of 1:3 and kept at 80-90°C for 2-4 hours. Then the whole mass is homogenized to a homogeneous state and cooled to 37-45°C. A mixture of waste products from the production of pepsin and hydrolysin preparations is added to it in the ratio of components 7:1:2, the pH of the medium is adjusted to 1.9-2.2 and kept for 3-6 hours. The resulting protein product is neutralized with caustic soda to pH 6.7-7.2. Achievable digestibility of the protein product from 83.5 to 85%). The disadvantage of the prototype is the need to correct the pH of the medium using dangerous caustic soda.

According to experts, see, for example, Antipova L. V., Shamkhanov C. Yu. Bioconversion of feather keratin under the action of various enzyme preparations. Izvestiya VUZov. Food Technology, No. 2-3, 2004, p. 33, enzymatic hydrolysis has a number of advantages, primarily associated with the production of desalted hydrolysates and with mild processing modes that maximally preserve the set of amino acids of natural keratins. Thus, the enzymatic "soft" hydrolysis makes it possible to obtain the most useful protein feed product from the KSS with the richest complex of amino acids and its maximum assimilation by animals with an ecologically clean production process (processing of raw materials requires only water and an enzyme) and low energy costs due to the processing of raw materials at low temperatures and pressures relative to chemical and hydrothermal hydrolysis options.

The objective of the invention is to quickly, cheap, environmentally friendly and completely safe processing of KSS using commercially available equipment into an easily digestible protein product (amino acid complex), which is used as a useful feed additive.

The technical result of the invention is to increase the processing time of the KSS by an average of 2 times compared to the prototype, to obtain a richer complex of amino acids in the resulting protein product and ensure its digestibility at a level of at least 85% with environmentally friendly and low-cost processing of raw materials.

The technical solution of the task and the technical result is provided by using the operation of coarse grinding of the KSS to a particle size of not more than 5 mm, further fine grinding of the raw material to a particle size of not more than 0.2 mm, homogenization of fine grinding by mixing and heating in the temperature range from 30 up to 60°C with the addition of water and subsequent fermentation of the heated mass with an enzyme containing keratin-cleaving proteases, separation of the fermented mass into liquid and solid fractions. The liquid fraction is an aqueous solution of the amino acid complex, the solid insoluble precipitate is repeatedly subjected to fine grinding, homogenization, fermentation and separation in the above cycle until it is completely fermented.

The essence of the invention lies in the fact that raw materials containing keratin, which are used as bird feathers and down, wool and bristles, are coarsely ground to a particle size of not more than 5 mm. then it is finely ground to a particle size of not more than 0.2 mm, the grinding is homogenized by stirring and heating in the temperature range from 30 to 60 ° C with the addition of water, the heated mass is fermented with an enzyme containing keratin-cleaving proteases, the fermented mass is separated into liquid and solid fractions, the solid insoluble precipitate is re-subjected in the specified cycle to fine grinding, homogenization, fermentation and separation until it is completely fermented. The block diagram of the proposed method is shown in Fig. one.

In an experimental example of the practical implementation of the proposed method, 100 kg of chicken feather and down were used as a feedstock, which was initially crushed to a maximum particle size of 5 mm for 10 minutes (including loading / unloading) using an IP-1M feather chopper with with a capacity of 1 t / h with the setting of a die of 10 mm, then the crushed feather and down were again crushed to a maximum particle size of 0.2 mm for 2 minutes on the same grinder "IP-1M", but with the setting of a die with holes of 2 mm . The resulting grinding was loaded with the addition of 500 liters of water into the "RDN-2" disperser with a capacity of 3 m ³ / h, where the homogenization process was carried out for 30 minutes, then the resulting mass was loaded into the "CKT-0.6" fermentation tank with a volume of 600 liters with the addition of 0.06 kg of the Protosubtilin enzyme, fermentation took place for 200 minutes at a mass temperature of 30 to 60 ° C, after which the fermented mass was separated in a BR-145 centrifuge into liquid and solid fractions for 15 minutes. As a result, 75 kg of dry matter in a 15% aqueous solution of an easily digestible amino acid complex were obtained with an achievable degree of product assimilation of 90% and 25 kg of solid insoluble sediment, which can also be processed until the fermentation is complete. Thus, the entire technological process according to the claimed method is environmentally friendly, does not require special permits and working conditions. At the same time, the process of obtaining a protein product from 100 kg of raw materials according to the claimed method in a specific example took 4 hours and 5 minutes at an actual cost of 8 kWh of electricity. The specified result is on average 2 times faster than the prototype method, which takes from 5 to 10 hours of working time and is about 3 times more economical in terms of energy costs, which fully meets the claimed technical result. The described implementation example is illustrated in Fig. 2.

Claims (1)

A method of processing raw materials containing keratin into an easily digestible protein concentrate - a feed additive, characterized in that coarsely crushed raw materials containing keratin, which are used as bird feathers and down, wool and bristles, to a particle size of not more than 5 mm, then it is finely crushed to a particle size of not more than 0.2 mm, grinding is homogenized by stirring and heating in the temperature range from 30 to 60 ^o C with the addition of water, the heated mass is fermented with an enzyme containing keratin-cleaving proteases, the fermented mass is separated into liquid and solid fractions, solid insoluble the precipitate is repeatedly subjected in the specified cycle to fine grinding, homogenization, fermentation and separation until it is completely fermented.

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